Numerical Modelling of Tidal Motion in the Southern Waters of Singapore

Abstract

Numerical modelling of tidal hydrodynamics in coastal seas has reached the level where it is now possible to obtain very reliable predictions of tidal currents, flows and water levels. The application of a nested computational technique allows for tidal motions in the coastal waters to be solved up to a reasonable degree of resolution. The technique involves an in-depth study of the selected sub domain in the overall problem domain utilizing the boundary data generated from a global/regional model covering a much larger area. This has been made possible on the PC due to the spectacular development in speed, memory capacity and reliability of such computers.

This paper describes in detail the development of a regional spatially two-dimensional numerical tidal hydrodynamics model (1km x 1km grid) involving an alternating explicit and implicit finite difference method suggested by Stelling (1984). The regional model is rigorously calibrated and validated using a 14 day spring-neap cycle of tidal levels and current measurements obtained from several field stations. A finer grid nested model 2DEAST (with mesh size 125m x 125m) is also developed using the boundary data generated by the regional model. The finer grid model is further validated with recent field measurements and the results of the simulations and field experiments are presented.